Delayed onset infections after lower third molar germectomy could be related to the space distal to the second molar.

The onset of delayed infection after lower third molar germectomy is influenced by the amount of distal space. This retrospective study aimed to determine whether the incidence of delayed onset infection is related to the space distal to the second molar. The ratio between the distal space and the crown width, measured according to the Ganss protocol on panoramic radiographs, was obtained for 218 surgical germectomies performed for orthodontic reasons in 134 patients. A delayed onset infection occurred following 20 germectomies at between 2 and 8 weeks after surgery; purulent exudates from the alveolus and swelling were present. In 16 of the 20 cases of infection, a Ganss ratio of <0.5 showed the almost complete absence of space distal to the second molar. This study found that the distal space was significantly and inversely correlated with delayed onset infection (P=0.004). From a clinical point of view, it is important for the surgeon to be aware that a higher Ganss ratio may indicate that a delayed onset infection is less likely to occur and that a lower Ganss ratio could indicate a greater likelihood of this type of infection, so that the patient can be properly informed.